1. Field of the Invention
The present invention relates to a temperature-humidity controller for a semiconductor device fabricating equipment, in which a humidifying or dehumidifying process of a processing air is simultaneously performed while the air is passed through a cooled water flow, and a controlling method thereof.
2. Description of the Related Art
Generally, in the fabricating processes of the semiconductor device, precise process conditions are required. In order to satisfy the conditions, it is necessary to properly control a temperature and a humidity of processing air which is supplied to a semiconductor device fabricating equipment (hereinafter, semiconductor equipment). In a conventional production system, a temperature-humidity controller (THC) for the semiconductor equipment is provided in an air supplying portion thereof so as to properly control the temperature and the humidity of the processing air. The air is treated to have a constant temperature and humidity by the THC, and then supplied to the semiconductor equipment. Therefore, the semiconductor device of good quality which satisfies the process conditions can be fabricated.
As shown in FIG. 1, the THC for the semiconductor equipment typically comprises a chemical filter, a dehumidifying means, a heating means and a humidifying means. They are separately disposed and communicated with each other by ducts. Therefore, if the air is introduced from the outside, a particular element, for example, ammonia contained in the air is filtered out by the chemical filter. Then, the air which the ammonia is filtered out is supplied through the duct to the dehumidifying means.
Sequentially, a predetermined amount of moisture contained in the air is removed by the dehumidifying means. The air is moved through the duct to the heating means and heated at a predetermined temperature. The air is then moved through the duct to the humidifying means so as to compensate for the moisture which is excessively eliminated by the dehumidifying means. After compensation of the moisture, the air is supplied to the semiconductor equipment.
Therefore, the air is supplied to the semiconductor equipment after being controlled through the above mentioned processes so as to have a proper temperature and a proper humidity (e.g. 23.degree. C., 40%).
In the above THC, the dehumidifying means generally comprises a compressor and a cooling pipe. A cooling gas, e.g. Freon is introduced into the cooling pipe. The air is contacted with the cooling pipe so as to be cooled, whereby the moisture in the air is facilely removed.
However, in the dehumidifying means which employs the Freon, there are some problems that environment and noise problems are arisen, due to the using of the Freon, and an occupation area of the equipment is increased.
Further, since each of the means which comprises of the equipment is separately disposed and connected with each other by the ducts, it is very difficult to maintain entirely the equipment.
To solve the problems, there is proposed an improved THC in which a semiconductor device instead of the Freon is employed.
FIG. 2 is a perspective view showing a conventional THC in which a semiconductor device is used.
As shown in FIG. 2, an air supplying port 102 is disposed at one side, e.g. an upper side of a housing 101. A chemical filter 110 by which a component of ammonia contained in the air is filtered and held to a desired amount (e.g., less than 1 ppb) is mounted at a lower portion of the air supplying port 102.
Meanwhile, through openings A are formed at both sides of the housing 101. A pair of dehumidifying means 120 are inserted into each through openings A. In the dehumidifying means 120, their surfaces are rapidly cooled by an operation of semiconductor devices so as to lower a temperature of the air, thereby dehumidifying the moisture contained in the air.
The dehumidifying means 120 comprises a cooling plate 121, a heat insulating plate 122, a radiating plate 123 and a cover plate 124. The cooling plate 121 is provided with a plurality of cooling fins 121a which are serially arranged and the semiconductor devices which are not shown. The heat insulating plate 122 serves to prevent a heat exchange between the semiconductor devices. The radiating plate 123 discharges the heat from the semiconductor devices to the outside. The cover plate 124 protects the semiconductor from a shock.
And, another through openings B are formed at the sides of the housing 101. A pair of heating means 130 are inserted into the through openings B. The heating means 130 are rapidly heated by a coil 131 and increases the temperature of the air, thereby compensating the temperature of the air which is cooled by the dehumidifying means 120.
Further, a humidifying means 140 is disposed at the lower portion of the housing 101. The humidifying means 140 sprays moisture through a ultrasonic oscillator so as to supplement the moisture of the air which is excessively dehumidified by the dehumidifying means 120.
As described above, the dehumidifying means 120, the heating means 130 and the humidifying means 140 which comprise the THC 100 for the semiconductor equipment are mounted on or inserted into the housing 101 and forms one unit.
Here, the semiconductor device is made of one of Bi.sub.2 Te.sub.3, Bi.sub.2 Se.sub.3 and Sb.sub.2 Te.sub.3 which have a good function of heat transfer.
The operation of the conventional THC like above will be described more fully.
The air which is introduced through the air supplying port 102 into the housing 101 is filtered by the chemical filter 110, and flows into the dehumidifying means 120. The air flows through the cooling fins 121a and is cooled. Therefore, the moisture contained in the air is rapidly liquidized and then fallen to the lower of the housing 101.
Sequentially, the air which is passed through the dehumidifying means 120 is introduced into the heating means 130 so as to compensate the temperature of the air which is cooled by the dehumidifying means 120. The air is then introduced into the humidifying means 140 which is disposed at the lower portion of the housing 101.
At this time, the humidifying means 140 sprays the moisture through the ultrasonic oscillator so as to supplement the moisture of the air which is excessively dehumidified by the dehumidifying means 120.
And then, the air is supplied through a blower (not shown) to the semiconductor equipment.
However, in the conventional THC as described above, there are some problems as follows:
First, since, after dehumidifying the air, it is necessary to heat and humidify again the air to obtain a desired temperature and humidity of the air, the processes for treating the air are complicated. And since the dehumidifying and humidifying processes are compulsively performed, energy loss is increased.
In addition, since the (heating type or ultrasonic type) humidifying means should be precisely controlled, it is very difficult to obtain a desired precision and it is frequently out of order.
Further, since the dehumidifying, heating and humidifying processes are separately controlled, the controlling operation is complicate and hard.